Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Introducing the new codename: Predicate Target: KDE 4.1 or 4.2

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Overview Problems to address Introduction to Predicate Predicate and KDE, Qt Kexi and Predicate plans

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Problems you can solve with Predicate Opening depends on document size even if you want to add one character Saving can take even longer

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's in the box? SQLite, MySQL and PostgreSQL support Cost of data opening and saving - independent of total size (unlike the case with big XML files)

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Database connectivity...for human beings? It should take a minute to start working with new data...

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Startup assistants to the rescue

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Unified database connection files [Connection1] caption=Tunnel to the main server encryptedPassword=************** engine=mysql port=3333 type=connection useLocalSocketFile=false user=test Admin defines server connections Users refer to them by name from any app

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE “Database import/export” assistants

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Database connectivity for...human beings? Want more users? Do not expect database administration skills.

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Problems you can solve with Predicate (2) Don't export, don't import. Share. (If possible) Document files come from the pre-network and pre-Internet era Avoid creating multiple versions of the same document ???

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Database connectivity for...human beings? The solution: local database files with ability of migrating to a server Implementation: SQLite 3

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Self-contained C library acting as SQL server for application it links to Features: Transactions Fast, constant access time (binary format) Command line interface Widely adopted

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE SQLite in KDE: Default Kexi (and thus, Predicate) database format Redland RDF's storage used by Soprano, which is used by NEPOMUK-KDE KDE PIM's Akonadi file-based storage Amarok's music collection Apps using QtSql can already use SQLite

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE in other software File format of Adobe Lightroom and Adobe Integrated Runtime Unified storage backend for Mozilla 2 components and extensions Included in Python, PHP and RealBasic Used by Google Desktop for the Mac Storage for AJAX apps in Google Gears

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE as system component in OS-es Part of Mac OS X 10.4 as embedded db engine; also used in Apple Mail and Aperture Integral part of Symbian 9.5 Service Management Facility replacing /etc/inittab in Solaris 10

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Can Predicate work for my app? Many applications are internally already database-like especially those employing MVC design pattern There's no need to deal with database internals (SQL, backend specifics)

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE By the way: Predicate and KIO Predicate is like KIO interface but for database and data structures

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's in the box? (2) Tools for creating data models are available at API level – no need to hardcode SQL statements and implement GUI t = new TableSchema(“ownership”); f = new Field(“id”, Integer); t->addField(f) f->setPrimaryKey(true); f = new Field(“owner”, Integer); t->addField(f); f = new Field(“model”, Integer); t->addField(f); f = new Field(“since”, Integer); t->setLookupFieldSchema("owner", lookupFieldSchema);

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's in the box? Built-in SQL parser provides probably the only Qt-based framework for employing type-safe SQL queries within applications

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's in the box? (3) Strong data typing and constraints (general feature of databases) Types and support for constraints generalized for typical usage

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate and QtSql

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate and ODBC ODBC specification is good but its implementation is simplistic (you may need to depend on 3 rd party commercial drivers) ODBC is not a solution as your appetite for generic data API increases So there's a plan for Predicate to wrap ODBC

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's in the box? (4) MS Access data import Database import from PostgreSQL and MySQL servers to a file

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – what's not included? Database administering and tuning tools (use dedicated for particular db backend) MySQL Administrator

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – how to get it? KDE SVN: trunk/koffice/kexi/kexidb/ will be moved to trunk/???/predicate/

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – Plans Providing Kexi plugins for other KDE apps: designer tools for tables, queries and forms, data widget, simple printouts Macros framework (in MS Access style) - a good companion for Kross

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – Plans Providing Kexi plugins for other KDE apps: table, query and form designer tools data-aware widgets simple printouts CSV import/export

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Predicate – Plans A way for dealing with native data sources and queries: deal with them as black boxes not available for direct data binding to the GUI, etc. Advantage: proprietary or not yet supported features can be used out of the box by knowledgeable users Side effects: executing native DML queries can introduce inconsistencies

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Kexi 2 - Plans More SQL features (grouping, improving the parser, alter table) Full text search, bindings to the upcoming KDE search facilities Reports using KOffice text layout engine with support for ODF

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Kexi 2 – Plans (2) Multithreading – optimization for large data sets Live data sharing ala (MS DDE) Dynamic Data Exchange, hopefully a companion to D-BUS Think about Qt-only and/or non-Qt users of the facilities?

Jarosław Staniek, aKademy 2007 Kexi - Data(base) Environment Universal Data Layer for KDE Thank you. Questions? Ideas? More info: API Docs: